Jump to content

Sammichsid, first test fail **FIXED**


husc

Recommended Posts

Hello,

I just finished the soldering part of the sammichSID kit, thanks to wilba for allready a lot of help, I received a replacement control surface pcb (my original had some cluttered holes!?) and the soldering part went great!

I am at page 18 of the build guide, doing the first voltage tests.

My power supply is a 12Vdc regulated.

When I power my sammich base pcb, I measure nothing at none of the points in the guide's picture. I read through older topics, but couldn't solve it. My solder points all look good!

My initial thought was a problem with the power supply, so I started with measuring J1: 12.7

Then the middle legs of the power switch: also 12.7

Nothing at J20 or J2.

I tested the parts around the power supply and got the 12.7 across the JBP's top left and bottom right pin!?

I tried a shunt and when I apply a shunt to both I do get power out of the regulators, but it's -1.98 ?

(I have shunts in place for a 12V hi power display and but them in JM1 and JM0 and in JP in the horizontal position.)

I am no expert and am still climbing a learning curve, thank you for any help!

Link to comment
Share on other sites

Just a shot in the dark, but, erm, have you turned it on?

yes! I didn't know what direction was 'on', but the power switch measurements answered that! When 'off' no output at the middle legs of the powerswitch, when 'on' 12.7 as described above!

Thanks for the quick reply.

Link to comment
Share on other sites

I resoldered 'c9' and the big fat cap and now i passed all the tests! So this step is FIXED!!

On to the next step, thanks and I hopefully check three times before I move on next time...

EDIT: attached control surface pcb, nothing.. rechecked the base, we're back at square 1! How can I check if I damaged the big fat cap or 'c9, because I can't get it to work anymore!

Edited by husc
Link to comment
Share on other sites

Using the voltage tests section of the guide, test continuity between points that have the same coloured dot. Then with power on, test voltages at those points, and report back any that aren't what you expect. Points marked 12V may not be exactly 12V depending on power supply. 9V and 5V should be very close (+/- 5%)

Link to comment
Share on other sites

They are all '0'!

I fixed the problem yesterday, 'c9' and the big fat cap weren't soldered well. I resoldered them and all the voltagetests passed! Within the 5% margin you mention.

As I continued assembling, I must have applied pressure or moved the big cap, because I didn't get any results testing the control surface. So I started over testing and the problem was again 'c9' and/or the big fat cap.

I resoldered them again, but this time it was a lot harder and I had to heat it longer. Now it doesn't work!

I am about to go out and buy a new big cap and replacement for C9, I don't know how to check if a cap is broken!

It is frustrating to solve something for just 10 minutes and then be in an even worse situation.

Is it wise to start replacing those parts now, or do you have any other suggestions?

Edited by husc
Link to comment
Share on other sites

The caps aren't vital for it to work, so there's probably a problem somewhere else.

Why did fixing the soldering on those caps solved my problem yesterday, I didn't touch anything else besides those two caps!?

Anyway, here are the pictures, thanks for your quick response!!

post-7644-021558600 1291625511_thumb.jpg

post-7644-070163400 1291625531_thumb.jpg

post-7644-008339200 1291625550_thumb.jpg

post-7644-026367500 1291625582_thumb.jpg

Link to comment
Share on other sites

Well... The soldering is pretty... :no:

When done right, the solder will flow through the whole and make a "tent" on both sides of the board. Which isn't the case anywhere on your PCB. With so many possible soldering problems, there's no point in debugging anything else. You're basically forcing intermittent problems that way. Go back and resolder everything that looks less than perfect.

I've highlighted some of the most obvious soldering problems in your pic:

post-3579-052657300 1291627867_thumb.jpe

Link to comment
Share on other sites

Ok, thank you!

I've redone some of them and am listening to the presets now! Everything works and it has a very very clean sound, I like it and hope to have some good time patching some myself.

I thought my soldering was ok, but I guess I was wrong.. that is very dissapointing and demotivating news. :sad: I was never trained and thought it myself over the years, always hoped practice made perfect.

Thanks for all the help and thank you Wilba for the great service on the control surface pcb! (do you want me to send you the bad pcb back? I can get back to you on that through email if you want?)

Link to comment
Share on other sites

Your soldering isn't all that bad... just the pads connected to ground plane... they're the ones that don't have a track connected nor a dark ring around them. Heat dissipates from the joint much quicker than other pads, so they need more heat (and/or better technique) to get the "tenting" to happen. If you have a temperature controlled iron, crank up the temp to 400 deg. just for those pads. Alternately, start with a small blob of solder on the tip, and approach the joint at a lower angle, so you're making more contact with the pad.

Send back the bad CS PCB, I am curious to find where it is shorting.

Link to comment
Share on other sites

... and buy nILS a beer :thumbsup:

Will do, I am in Berlin quiet often and have a serious Becks addiction! :D

Thank you very much for those soldering tips, I need more of those, just soldering by myself doesn't help, but I am getting better and so far all my projects work and they still do!

The CS PCB was the one with 'filled up' holes! I will send it to you.

You guys both rock. I will do a sammichSID demo later this week, dedicate it and share! :thumbsup:

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...